Kolowratia eruciformis Ridl.

Docot, Rudolph Valentino A., Haevermans, Thomas & Poulsen, Axel Dalberg, 2025, Is Alpinia luteocarpa the correct scientific name for the ornamental red bamboo ginger?, Willdenowia 55 (1), pp. 79-90 : 84-86

Kolowratia eruciformis Ridl. in Philipp. J. Sci., C 4: 182. 1909 (‘ erucaeformis ’). – Lectotype (designated here): Philippines, Mindanao, Surigao del Norte, Bucas Grande Island , 4 Oct 1906, E. D. Merrill 5258 (US [barcode 00092931]; isolectotype: E [barcode E00119608]). – Fig. 1, 4.

Description — Terrestrial herb forming a loose clump. Rhizome c. 5 cm in diam., scales thin, 26–32 × 30– 40 mm, glabrous, brown, margin pubescent, apex acute. Pseudostem 1–2 m long, mostly erect, distance between two leafy shoots c. 8 cm, base 8–9 cm in diam., with 40– 60 laminae per shoot; sheaths glabrous, mid-green; ligule shallowly bilobed, 1–3 mm long, with a few scattered hairs, light green, base reddish; lamina sessile, linear, 22– 43 × 2–3 cm, glabrous on both surfaces, light green abaxially, mid-green adaxially, non-plicate, subcoriaceous, base subcordate, margin entire, apex sharply attenuate. Inflorescence terminal on leafy shoot, a panicle, to 30 cm long, variously arching; free part of peduncle 3–15 cm long, glabrous to slightly puberulous, light green; rachis up to 15 cm long, puberulous, light green; cincinni 4–10, sessile, alternately arranged along rachis, 2–4 cm apart, elongate with age up to 10 cm; bracts open to base, ovate to oblong, 40–60 × 15–18 mm, puberulous, occasionally glabrous toward apex, mid-green, brown with age, brownish red at base, both surfaces shiny, apex acute; pedicels 12–26 mm long, puberulous, reddish white at base, becoming greenish white toward apex; bracteoles distichously arranged, spathaceous, 23–26 mm long, keeled, split to 15 mm from apex, puberulous, brown, apex mucronate, mucro to 1 mm long, pubescent. Flowers 5.5–9 cm long, 5–10 per cincinnus, c. ¾ of pedicel covered by bracteole; calyx tube spathaceous, 20–30 mm long, split to 13 mm from apex, glabrous, deep red, apex 2- or 3-dentate, sparsely hairy; floral tube 24–28 mm long, glabrous outside, pubescent at base, densely pubescent toward apex inside, white; dorsal corolla lobe ovate, 22–25 × 17–25 mm, concave, glabrous, white, central part thickened and tinged red or pink adaxially, appearing shallowly trilobed when flattened, central lobe acute and cucullate; lateral corolla lobes overlapping, ovate, 23–25 × 13–20 mm, glabrous, white, central part thickened, apex acute and cucullate, slightly tinged red; labellum reduced, somewhat triangular, fleshy, to 5 × 5 mm, pubescent, brownish white or yellowish white, apex acute; lateral staminodes absent; stamen 12–15 mm long; filament 2–4 mm long, pubescent, cream-white; anther 10–12 × 4–6 mm, connective pubescent, reddish yellow; anther crest c. 1 × 1.5 mm, petaloid, pubescent, reddish yellow or whitish yellow, apex truncate; thecae 10–12 × 1–2.5 mm, pubescent, white, dehiscing from c. 2 mm above base of theca to c. 1 mm below apex; style 32–37 mm long, pilose, white; stigma funnel-shaped, somewhat flattened, c. 2 × 4 mm, white, ostiole elliptic, with hairs; epigynous gland globose, c. 4 × 4 mm, glabrous, yellow, enclosing base of style; ovary subglobose, 5–10 × 4–9 mm, trilocular, glabrous, light green, coriaceous, placentation axile. Fruit oblong, 3.3–4.1 × 2.1–3 cm, glabrous, mid-green when young, becoming orange then yellow when mature, calyx persistent; seeds up to 85 per fruit, c. 5 × 3 mm, angular subglobose, glabrous, black, enclosed by a white aril.

Etymology and common name — The specific epithet refers to the rocket-like ( Eruca -like) inflorescence. Ridley (1909) spelled it ‘ erucaeformis ’, which is corrected to eruciformis following ( Turland & al. 2018: Art. 60.10). No local name is recorded in the Philippines. Commonly known as the red bamboo ginger around the world.

Distribution — Native in the Philippines to the provinces Laguna, Leyte and Surigao del Norte ( Fig. 3). Kolowratia eruciformis is also believed to be native in Sagada, Mountain Province (Hidenobu Funakoshi pers. comm.). Cultivated in tropical regions around the world.

Habitat — Kolowratia eruciformis inhabits semi-shaded secondary forests along ridges or near mangrove areas at 15–400 m elevation.

Phenology — Flowering and fruiting throughout the year.

Provisional conservation status — Using the IUCN red list categories and criteria ( IUCN Standards and Petitions Committee 2022), Kolowratia eruciformis is preliminarily assessed as Vulnerable (VU B1ab(iii)+2ab(iii); D). The area of occupancy (AOO) is estimated to be less than 2000 km 2 (total AOO is 20 km 2) while the extent of occurrence (EOO) is estimated to be less than 20,000 km 2 (total EOO is 9271.79 km 2). Only specimens collected in the wild were used for this assessment, 200–250 mature lished, it is useful to know where it belongs. This makes sense because A. D. E. Elmer 17977 was collected at Mount Makiling where K. eruciformis occurs, whereas L. haenkei has never been seen or documented there.

Selected specimens examined — PHILIPPINES: LUZON: LAGUNA : Los Baños, Mount Makiling, Jun–Jul 1917, A. D. E. Elmer 17977 ( BM [2 sheets], FI, GH, K, NY, P, PH, S, US); 31 May 1958, J. Sinclair & G. E. Edaño 9472 (E, PNH); 15 Feb 2016, R. V. A. Docot & al. 28 (L, SING, USTH); 15 Nov 2016, R. V. A. Docot & al. 92 ( FEUH, PNH, USTH). — VISAYAS: LEYTE: Ormoc City, Mount Janagdan, 6 Apr 1950, G. E. Edaño 12001 ( GH, PNH). — MINDANAO: SURIGAO DEL NORTE: Bucas Grande Island , Socorro , Barangay San Roque , Sitio Sabang , 09°37'47.4"N, 125°54'09.6"E, 13 Jul 2019, C. B. M. Domingo & al. SDN19-018 ( FEUH incl. spirit, L, PNH, SING, USTH). — CULTIVATED MATERIAL: Cultivated at Lyon Arboretum , Hawaii , U.S.A., source of material Thailand but origin Philippines, accession number L-82.1616, 4 Sep 1985, K. M. Nagata 3366 (E); 27 Apr 1987, K. M. Nagata 3619 (E); 15 Jun 1999, W. J. Kress & H. Kennedy 99-6403 (US); 7 Jan 2005, W. J. Kress & Q.-J. Li 05-7785 ( US). Cultivated at Fairchild Tropical Garden, Miami , U.S.A., source of material Thailand but origin Philippines, 16 Aug 1987, N. Woessner s.n. (E). Cultivated at Royal Botanic Garden Edinburgh , U.K., source unknown, accession number 87S5719, Oct 1996, A. Rangsiruji & al. 2 (E). Cultivated at Singapore Botanic Gardens , Singapore, origin Luzon, Philippines, 29 Oct 2010, J. Leong-Skornickova JLS794 ( PR, SING) .